Evidence of members of the Chlamydiales in bovine abortions in England and Wales

Despite the economical importance and welfare issues associated with bovine abortion, as well as the potential zoonotic implications, the rate of diagnosis remains low with a cause of abortion only identified in around 22.5 per cent of submissions received at veterinary investigation centres in England, Wales and Scotland (VIDA, anon). Though diagnosis rates are somewhat higher for cases in which complete sample sets are available for analysis (52 per cent), this low rate of diagnosis could in part be explained by the presence of previously unidentified infectious abortifacient agents.Chlamydia abortus is recognised as a known cause of ruminant abortion, however, several newly recognised species of Chlamydia-related organisms (CROs) have recently emerged as putative ruminant abortifacients. Studies performed on placentas obtained from suspected cases of infectious bovine abortion in Switzerland identified the presence of Parachlamydia, Waddlia and other non-classified CROs using both molecular and immunohistochemical techniques (Borel and others 2007, Ruhl and others 2009, Blumer and others 2011). These findings have been further supported by studies conducted on Scottish bovine abortion samples in which the identification of Parachlamydia, Rhabdochlamydia and Neochlamydia species in bovine fetal and placental tissue samples was demonstrated (Deuchande and others 2010, Wheelhouse and others 2010, 2011). However, to date no studies have been carried out to investigate the incidence of CROs in bovine abortion in other regions of the UK.Samples were obtained from bovine abortion material submitted to regional laboratories of the former Veterinary